Power storage device

Abstract

The invention provides a power storage device capable of preventing reduced energy efficiency of the power storage device and of avoiding variations in temperature distribution. The power storage device includes a positive electrode and a negative electrode, and a solid electrolyte layer placed between the positive electrode and the negative electrode and including a group of particles, wherein the density of particles in a first area of the solid electrolyte layer is lower than the density of particles in a second area which has higher heat radiation than the first area.

1. A power storage device comprising:
 a positive electrode and a negative electrode; and 
 a solid electrolyte layer placed between the positive electrode and the negative electrode and including a group of particles, 
 wherein a density of particles per volume in a first area of the solid electrolyte layer is lower than a density of particles per volume in a second area which has higher heat radiation than the first area such that current value is lower, and resistance higher, in the first area than in the second area, in order to reduce heat production in the first area, and to prevent variation in temperature distribution in a predetermined direction in the power storage device, the predetermined direction being a direction orthogonal to a stacking direction of the positive electrode, the negative electrode and the solid electrolyte layer, 
 wherein the first area is an area located in the predetermined direction on a central portion side of the solid electrolyte layer, and the second area is an area located in the predetermined direction closer to an end portion than the first area. 
 
     
     
       2. The power storage device according to  claim 1 , wherein an average diameter of the particles in the first area is larger than an average diameter of the particles in the second area. 
     
     
       3. The power storage device according to  claim 1 , wherein the solid electrolyte layer includes a bonding agent for bonding the particles, and
 an amount of the bonding agent in the first area is larger than an amount of the bonding agent in the second area. 
 
     
     
       4. The power storage device according to  claim 3 , wherein an average diameter of the particles in the first area is generally equal to an average diameter of the particles in the second area. 
     
     
       5. The power storage device according to  claim 1 , wherein a density of the particles is reduced from the end position to the central portion of the solid electrolyte layer continuously or stepwise. 
     
     
       6. A power storage device comprising:
 a positive electrode and a negative electrode; and 
 a solid electrolyte layer placed between the positive electrode and the negative electrode and including a group of particles, 
 wherein a thickness of a first area of the solid electrolyte layer is larger than a thickness of a second area which has higher heat radiation than the first area such that current value is lower, and resistance higher, in the first area than in the second area, in order to reduce heat production in the first area, and to prevent variation in temperature distribution in a predetermined direction in the power storage device, the predetermined direction being a direction orthogonal to a stacking direction of the positive electrode, the negative electrode and the solid electrolyte layer, 
 wherein the first area is an area located in the predetermined direction on a central portion side of the solid electrolyte layer, and the second area is an area located in the predetermined direction closer to an end portion than the first area. 
 
     
     
       7. The power storage device according to  claim 6 , wherein a thickness of an area of each of the positive electrode and the negative electrode that corresponds to the first area is smaller than a thickness of an area corresponding to the second area. 
     
     
       8. A power storage device comprising:
 a positive electrode and a negative electrode; and 
 a solid electrolyte layer placed between the positive electrode and the negative electrode and including a group of particles, 
 wherein a material of the particles in a first area of the solid electrolyte layer is different from a material of the particles in a second area which has higher heat radiation than the first area such that current value is lower, and resistance higher, of the particles forming the first area than of the particles forming the second area, in order to reduce heat production in the first area, and to prevent variation in temperature distribution in a predetermined direction in the power storage device, the predetermined direction being a direction orthogonal to a stacking direction of the positive electrode, the negative electrode and the solid electrolyte layer, 
 wherein the first area is an area located in the predetermined direction on a central portion side of the solid electrolyte layer, and the second area is an area located in the predetermined direction closer to an end portion than the first area. 
 
     
     
       9. A power storage device comprising:
 a positive electrode and a negative electrode; and 
 a solid electrolyte layer placed between the positive electrode and the negative electrode and including a group of particles, 
 wherein a density of particles per volume in a first area of the solid electrolyte layer is lower than a density of particles per volume in a second area which has higher heat radiation than the first area such that current value is lower, and resistance higher, in the first area than in the second area, in order to reduce heat production in the first area, and to prevent variation in temperature distribution in a predetermined direction in the power storage device, the predetermined direction being a direction orthogonal to a stacking direction of the positive electrode, the negative electrode and the solid electrolyte layer, 
 wherein the power storage device is disposed adjacent to a heat source in the predetermined direction, 
 wherein the first area is an area located in a predetermined direction closest to the heat source, and the second area is an area located in the predetermined direction away from the heat source than the first area. 
 
     
     
       10. A power storage device comprising:
 a positive electrode and a negative electrode; and 
 a solid electrolyte layer placed between the positive electrode and the negative electrode and including a group of particles, 
 wherein a thickness of a first area of the solid electrolyte layer is larger than a thickness of a second area which has higher heat radiation than the first area such that current value is lower, and resistance higher, in the first area than in the second area, in order to reduce heat production in the first area, and to prevent variation in temperature distribution in a predetermined direction in the power storage device, the predetermined direction being a direction orthogonal to a stacking direction of the positive electrode, the negative electrode and the solid electrolyte layer, 
 wherein the power storage device is disposed adjacent to a heat source in the predetermined direction, 
 wherein the first area is an area located in the predetermined direction closest to the heat source, and the second area is an area located in the predetermined direction away from the heat source than the first area. 
 
     
     
       11. A power storage device comprising:
 a positive electrode and a negative electrode; and 
 a solid electrolyte layer placed between the positive electrode and the negative electrode and including a group of particles, 
 wherein a material of the particles in a first area of the solid electrolyte layer is different from a material of the particles in a second area which has higher heat radiation than the first area such that current value is lower, and resistance higher, of the particles forming the first area than of the particles forming the second area, in order to reduce heat production in the first area, and to prevent variation in temperature distribution in a predetermined direction in the power storage device, the predetermined direction being a direction orthogonal to a stacking direction of the positive electrode, the negative electrode and the solid electrolyte layer, 
 wherein the power storage device is disposed adjacent to a heat source in the predetermined direction, 
 wherein the first area is an area located in the predetermined direction closest to the heat source, and the second area is an area located in the predetermined direction away from the heat source than the first area.